Getting a shock in a shower.

[mktdeeping]

Hi all. Sort of an interesting one. I had a call from a client to say she is getting a shock when using the shower. I told her not to use it and I’d go next day to have a look. I thought easy job, just replace the shower. I was wrong….it wasn’t an electric shower!
I checked from an earth to the shower drain gulley, the tile grout, the wall behind the shower and the door bar on the floor where the carpet joined the floor tiles. All were giving between 18v and 27v. Water had obviously been leaking behind the shower seal and through grout etc. must be a joint under the floor somewhere that’s getting damp. The upstairs lighting circuit seemed to be the culprit with an earth to live fault and when isolated at the consumer unit the voltage disappeared. Time to get floor up or ceiling down. The client said don’t do any more investigation even though it’s still live and he wanted to leave things until everything dries out….could be weeks or months. I wasn’t happy with that so I put RCBO on the lighting circuit (which didn’t trip) and gave him a letter explaining the danger and covering myself and will wait to hear from him when he wants me to go back.
Anyone else had this sort of issue?

 

[CG_Sparks]

I went to look at a job like this a few years ago. My customer had a rental house, where there was an upstairs bedroom that had a newly built stud wall to make an ensuite, which he had built himself, to save money. Anyway, one day he phoned and said one of his tenants kept getting frequent shocks when touching the mixer tap in the shower cubicle at night and the RCD kept tripping. So I went round and checked voltages between the mixer tap and the metal frame of the shower cubicle and got between 100 - 187v! But only when the living room lights were on below the ensuite! Turned out that the landlord had managed to use really long screws for the metal frame, which had somehow engaged a downstairs 2-way switch cable under the floorboards, without engaging the CPC of the cable! So whenever those lights were on the tenant got a shock!